Posts Tagged ‘laser’

Laser Pointer Used as an AF Assist Tool

Photographer Adrian Onsen wanted to use the AI Servo autofocus mode on his Canon 40D in low-light situations, but found that the AF assist beam is only emitted once until focus is achieved rather than every time the camera needs to refocus. He then purchased a laser pointer from a dollar store, disassembled it to obtain a defocused beam of light, and attached it to the top of his camera. The hacked-together AF assist tool ended up working pretty well — Onsen was able to shoot sharper photos at a dance club without anyone noticing the extra light. To learn more check out his in-depth writeup here.

AF Assist tool (via Hack a Day)

What Laser Light Can Do to Your Precious DSLR Sensor

We all know pointing your DSLR directly at the sun for extended periods of time isn’t too healthy for your sensor, but what about laser lights like the ones used at concerts? Turns out those can be even more lethal for your camera, even with very brief exposures.

Here are two videos shot with DSLR cameras that show a laser briefly passing over the camera and damaging the sensor permanently. Both were shot with Canon 5D Mark II cameras:

See the white line that appears immediately after the laser sweeps across?
Read more…

“Photo Grandpa” Shoots with Laser Rigs

Belgian photographer fotoopa (“photo grandpa” in Dutch) shoots ultra-high speed photographs with laser rigs he builds himself. He tells us:

I’m retired, and work inside in the winter making high-speed pictures of water figures. In the springtime and summer I’m outside to capturing insects in-flight. I have a mechanics (15 years experience) and electronics (26 years) background, but photography was always my hobby.

All of my equipment is do-it-yourself. Macro photography has always been one of my favorite types of photography.

Descriptions and diagrams of his rigs are posted for 2008 and 2009. Here’s a glimpse at one of his setups:

To capture insects in flight, his rig detects the insects using two crossed laser beams. This causes a “superfast electro magnet” to trigger the shutter, which opens and closes in less than 5 milliseconds. Shooting at f/22 and ISO 100, he uses 2 or 3 external flashes at minimum power to obtain sufficient light at so short a shutter speed. He adds,

For insects in-flight, a special second shutter system provides the short shutter-lag of ~7 msec necessary. There is also a high-tech IR laser system with an extra third macro-lens and internal AVR controller. In 40 microseconds, this system sees (via the reflected IR light into the detector lens) if an object comes in focus, and give the information to the central CPLD hardware controller that drive the whole system. In this manner even very fast moving insects are in perfect focus in the picture frame.

In the winter, the water figures are done indoors. First done in 2004, I covered a speaker with a membrane, and put a digital wave through it to move the fine colored droplets on the membrane. This provides wonderful images and an unlimited number of possibilities.

For 2010 I built a 3D stereo setup to capture all the high-speed macro pictures in 3D. The setup uses 2 DSLR Nikon cameras, the D200 and D300

To see more of these amazing photographs, you can check out fotoopa on Flickr or on pbase.

(via MAKE)


Image credit: Photographs by fotoopa and used with permission.